Tuberculosis causes 2 million deaths worldwide annually, and development of an effective vaccine is a critical research goal. CFP10 is a secreted M. tuberculosis protein which stimulates T-cells to produce IFN-y and exhibit cytotoxic T lymphocyte activity. Our preliminary data demonstrate that CFP1071-90 is recognized by a high percentage of persons with latent tuberculosis infection, and that it contains at least two epitopes that are recognized by persons expressing different HLA class I and class II alleles. The presence of multiple epitopes, recognized in the context of several HLA molecules, makes CFP1071-90 an attractive vaccine candidate. We will evaluate the immunogenicity and protective capacity of CFP1071-90 through the following aims: 1) Compare the immunogenicity of systemic and mucosal immunization with a DNA vaccine encoding CFP1071-90 in transgenic mice expressing human HLA class I and class II alleles. This will be achieved by immunizing transgenic mice expressing DRB1*0401, A*0201 or both molecules, with a DNA vaccine encoding CFP1071-90. Lung and splenocyte T-cell subpopulations will be characterized by cell surface phenotype and by functional capacity to exhibit CTL activity, and produce IFN-y. (2) Determine the protective efficacy of a DNA vaccine encoding CFP1071-90 in transgenic mice expressing HLA class I and class II alleles. The capacity of the vaccines to reduce the bacillary burden and lung pathology in M. tuberculosis-infected mice will be determined. This proposal will evaluate the efficacy in vivo of a very promising candidate for inclusion in an antituberculosis subunit vaccine. As far as we are aware, this represents the first use of a vaccine expressing a short microbial peptide that stimulates CD4+ and CD8+ T-cells in animals expressing human class I and class II HLA molecules. These studies will provide the opportunity to determine the relative importance of CD4+ and CD8+ T-cells in immunity against M. tuberculosis in a humanized experimental system. [unreadable] [unreadable]